<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>17.Symbol的内置属性</title>
</head>
<body>
    <script>
        class Person{
            static [Symbol.hasInstance](){
                console.log('我被用来检测类型了');
            }
        }
        let o = {};

        console.log(o instanceof Person);
    </script>
</body>
</html>